During a cell-assembling process of liquid crystal panels, a rubbing step is performed by rubbing an alignment film surface of a substrate in a certain direction with a certain force using a roller wrapped with nylon cloth or cotton cloth so as to form channels which allow liquid crystals to have directional alignment and pre-tilt angle. Such step is also referred to as alignment technology of liquid crystal molecules. The effect of alignment directly affects qualities of liquid crystal devices, thus the alignment technology has extremely strict requirements on the roller; wherein, apart from a material of the roller that may affect qualities of the roller such as precision and deformation resistance, a storing means of the roller may also have considerable influence thereto. Furthermore, manufactures recently have increasingly higher requirements on cost and efficiency for storing rollers.
A currently known roller-storage system merely can achieve semi-automatic roller pick-and-place operation. The system includes a roller storage and a robot configured for roller pick-and-place with a structure illustrated in FIG. 1 and FIG. 2, respectively. The robot is a multi-joint apparatus freely movable as a whole, including a plurality of freely rotatable joints, stretching arms 12 disposed between the joints, and a clamping arm 14 configured to clamp the roller; the roller storage includes a clamping clip 16 and a clamping slot 15 which are configured to clamp the roller, and a storing platform; as illustrated in FIG. 3, a roller transporter used as the device transporting the roller includes wheels 17 and a roller transport platform 18 on which the roller can be placed. With such semi-automatic roller storage system, the roller transporter is fixed at a certain position in the storage by manual works so as to precisely position the robot to pick up a roller from the roller transporter, then the clamping arm of the robot clamps the roller tightly and transports the same into the clamper 16 and the slot 15 at a corresponding position on the storing platform; when it is determined that the roller 1 has been placed in position, the robot returns to an original pre-set position and waits for a pick-and-place instruction for another roller 1.
As above, the currently known semi-automatic roller storage system mainly relies on a precise positioning of the robot to achieve roller pick-and-place operation, which is a complicated and slow process and may heavily influence the pick-and-place efficiency; moreover, when stored for a long period of time, the roller is likely to have bending deformation because it is placed at an inclined angle, which may influence qualities, performances and a service life of the roller.